<!DOCTYPE html>
<html>
<head>
    <title>实例 - 下拉菜单（Dropdowns） </title>
    <link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">


</head>
<body>


<div class="dropdown">
    <button type="button" class="btn dropdown-toggle" id="dropdownMenu1"
            data-toggle="dropdown">
        主题 <span class="caret"></span>
    </button>
    <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">Java</a>
        </li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">数据挖掘</a>
        </li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">
                数据通信/网络 </a>
        </li>
        <li role="presentation" class="divider"></li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">分离的链接</a>
        </li>
    </ul>
</div>

对齐
通过向 .dropdown-menu 添加 class .pull-right 来向右对齐下拉菜单。下面的实例演示了这点：

<div class="dropdown">
    <button type="button" class="btn dropdown-toggle" id="dropdownMenu2"
            data-toggle="dropdown">主题 <span class="caret"></span>
    </button>
    <ul class="dropdown-menu pull-right" role="menu"
        aria-labelledby="dropdownMenu2">
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">Java</a>
        </li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">数据挖掘</a>
        </li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">
                数据通信/网络 </a>
        </li>
        <li role="presentation" class="divider"></li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">分离的链接</a>
        </li>
    </ul>
</div>

标题

您可以使用 class dropdown-header 向下拉菜单的标签区域添加标题。下面的实例演示了这点：


<div class="dropdown">
    <button type="button" class="btn dropdown-toggle" id="dropdownMenu3"
            data-toggle="dropdown">
        主题 <span class="caret"></span>
    </button>
    <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu3">
        <li role="presentation" class="dropdown-header">下拉菜单标题</li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">Java</a>
        </li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">数据挖掘</a>
        </li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">
                数据通信/网络 </a>
        </li>
        <li role="presentation" class="divider"></li>
        <li role="presentation" class="dropdown-header">下拉菜单标题</li>
        <li role="presentation">
            <a role="menuitem" tabindex="-1" href="#">分离的链接</a>
        </li>
    </ul>
</div>





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